Use Of Intraoperative Neuromonitoring In Posterior Fossa Surgery

Abstract

Case summary: A 9-year-old female presented with central and left peripheral cerebellar signs. Imaging showcased a left cerebellar hemisphere cystic mass with a radiological diagnosis of a pilocytic astrocytoma. Suboccipital craniotomy was done with a transcortical approach. Tumor mural nodule resection was achieved. Intraoperative adjuncts included Intraoperative Neuromonitoring (ION) with Somatosensory Evoked potentials, Motor Evoked Potentials, Electromyography of cranial nerves 5, 6, 7, 9, 10, 11 and 12. The post operative course was unremarkable. Discussion: The posterior fossa surgeries are rife with complications at a higher rate than supratentorial surgeries. Sticking to good surgical principles and optimization of anesthesia have a bearing in preventing postoperative complications. However, ION as an adjunct helps to alert the surgeon of pending neurological damage leading to a good onco-functional balance postoperatively. There is concern for less-than-optimal surgical resection with use of ION especially with false positive recordings. ION in the posterior fossa can be useful for expanding the surgical corridors, but is it necessary in all surgical ventures?